Movement recognition in video file

[mindmaster32 at gmail.com]

Hi,

I am looking for a python tool or module that helps me build a script
that can perceive object moves in a video file captured by a (web)
camera. My main goal is to be able to count people entering a store
using the store's surveillance camera.

I know of some packages like Eyesweb (gestural recognition package) or
Pure Data's module called GEM, but I don't know any written in python.

Thanks